Process for the Manufacture of Bobbins and Booklets of Sheets of Roll-Your-Own Cigarette Paper

ABSTRACT

The present invention relates to a process for the manufacture of bobbins, of sheets and of a booklet of sheets of roll-your-own cigarette paper and to a process for the manufacture of a booklet of sheets of roll-your-own cigarette paper.

TECHNICAL FIELD

The invention relates to sheets of paper for roll-your-own cigarettes.

PRIOR ART

The sheets of roll-your-own cigarette paper exhibit a rectangulargeneral shape, to which is applied an adhesive strip along one of thelong edges of the rectangle. These sheets are sold in the form of abooklet which can comprise approximately a hundred sheets. In order tomake a roll-your-own cigarette, the user takes a sheet from his booklet,places tobacco on the sheet, then forms the roll-your-own cigarette bymoistening the adhesive strip and by superimposing it on the sheet

Conventionally, the sheets of roll-your-own cigarette paper aremanufactured from webs of roll-your-own cigarette paper cut into bobbinsof roll-your-own cigarette paper, the width of the bobbins beingsubstantially equal to the width of the sheets. An adhesive strip issubsequently applied to one of the two long edges of the bobbin ofroll-your-own cigarette paper in the machine direction and then thebobbin is dried. The dried bobbin is subsequently cut into sheets ofroll-your-own cigarette paper.

The roll-your-own cigarette paper exhibits a very low grammage, whichcan thus easily be torn during the manufacture of the sheet. One of themost problematic steps is that of the application of the adhesive stripto the bobbin. This is because this step is conventionally carried outusing pressurized nozzles which can easily tear the bobbin. This is allthe truer when the width of the bobbin is less than 10 cm. Furthermore,the adhesive strip is deposited along one of the long edges of thebobbin; a portion of the adhesive strip may thus be deposited outsidethe bobbin so that the material is lost and the amount of adhesive stripis not sufficient for a cigarette to be formed.

Because of these problems, conventional processes for the production ofthe roll-your-own cigarette paper have to be regularly stopped. The rateof forward progression of the paper in these processes can also beoptimized.

For all these reasons, the productivity of these processes is notoptimal.

TECHNICAL PROBLEM

There thus exists a need for an effective solution for improving theproductivity of the process for the manufacture of the sheets ofroll-your-own cigarette paper.

It is thus to the credit of the inventors to have found that it ispossible to meet this need by applying several moisture-activatableadhesive strips to a web of roll-your-own cigarette paper and then tocut the strip into bobbins.

SUMMARY

Thus, a first aspect of the invention is a process for the manufactureof bobbins of roll-your-own cigarette paper comprising the followingsteps:

a) applying n moisture-activatable adhesive strips to a web ofroll-your-own cigarette paper in order to obtain an adhesive web ofpaper, each of the n moisture-activatable adhesive strips extending inthe machine direction, and

b) cutting the adhesive web of paper in the machine direction along then-1 moisture-activatable adhesive strips in order to obtain n bobbins ofroll-your-own cigarette paper, each bobbin of roll-your-own cigarettepaper comprising a moisture-activatable adhesive strip along one ofthese long edges, n being an integer greater than or equal to 2.

Unlike the conventional process in which a single moisture-activatableadhesive strip is deposited directly on a bobbin of roll-your-owncigarette paper, the n moisture-activatable adhesive strips aredeposited by the process of the invention on a web of roll-your-owncigarette paper, the width of which is greater than the width of abobbin of roll-your-own cigarette paper. The risk of tearing theroll-your-own cigarette paper during step a) with the process for themanufacture of a bobbin of roll-your-own cigarette paper of theinvention is lower than with the conventional process. Thus, it is notnecessary to regularly stop the process for the manufacture of a bobbinof roll-your-own cigarette paper of the invention.

It is also more efficient to apply the n moisture-activatable adhesivestrips to a web of roll-your-own cigarette paper and then to cut saidweb of roll-your-own cigarette paper into n bobbins of roll-your-owncigarette paper than to cut a web of roll-your-own cigarette paper inton bobbins of roll-your-own cigarette paper and to apply a single stripto each of the n bobbins of roll-your-own cigarette paper.

Furthermore, only one of then moisture-activatable adhesive strips isapplied to one of the long edges of the web of roll-your-own cigarettepaper. Thus, in comparison with the conventional process, the process ofthe invention makes it possible to greatly limit the loss ofmoisture-activatable adhesive.

Consequently, the productivity of the process for the manufacture of abobbin of roll-your-own cigarette paper of the invention is greater thanthe productivity of the conventional processes for the manufacture of abobbin of roll-your-own cigarette paper.

Another aspect of the invention is a process for the manufacture of asheet of roll-your-own cigarette paper comprising a step c) of cutting abobbin of roll-your-own cigarette paper manufactured by the process forthe manufacture of a bobbin of roll-your-own cigarette paper of theinvention.

Another aspect of the invention is a process for the manufacture of abooklet of sheets of roll-your-own cigarette paper comprising a step d1)of formation of a stack of sheets of roll-your-own cigarette paper whichare manufactured by the process for the manufacture of a sheet ofroll-your-own cigarette paper of the invention.

Another aspect of the invention is a process for the manufacture of abooklet of sheets of roll-your-own cigarette paper comprising a step d2)of formation of a stack of bobbins of roll-your-own cigarette paperwhich are manufactured by the process for the manufacture of a bobbin ofroll-your-own cigarette paper of the invention, followed by a step e) ofcutting the stack of bobbins.

The processes of the invention make it possible to advantageouslyproduce a paper, in the form of a bobbin or of a sheet, forroll-your-own cigarettes comprising a moisture-activatable strip with agreater productivity than the productivity of the conventionalprocesses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an adhesive web of paper obtained at the end of thestep a) of the process of the invention with four moisture-activatableadhesive strips applied thereon.

FIG. 2 illustrates four bobbins obtained at the end of the step b) ofthe process of the invention.

DETAILED DESCRIPTION OF THE INVENTION

According to a first aspect, the invention is a process for themanufacture of bobbins of roll-your-own cigarette paper comprising thefollowing steps:

a) applying n moisture-activatable adhesive strips to a web ofroll-your-own cigarette paper in order to obtain an adhesive web ofpaper, each of the n moisture-activatable adhesive strips extending inthe machine direction, and

b) cutting the adhesive web of paper in the machine direction along then-1 moisture-activatable adhesive strips in order to obtain n bobbins ofroll-your-own cigarette paper, each bobbin of roll-your-own cigarettepaper comprising a moisture-activatable adhesive strip along one ofthese long edges, n being an integer greater than or equal to 2.

Within the meaning of the present invention, the term “roll-your-owncigarette paper” is understood to mean paper used for rollingcigarettes. It can be manufactured from the pulp of wood, tobaccofibers, hemp fibers, flax fibers, sisal fibers, fibers of the shellprotecting the cocoa bean, cannabis fibers, rice straw, alfa grassfibers and mixtures thereof. The roll-your-own cigarette paper exhibitsa lower grammage and is thinner than the paper of rolled marketedcigarettes. For example, the grammage of the rolling paper, measuredoutside the adhesive strip, may be between 10 g/m² and 50 g/m², inparticular between 12 g/m² and 25 g/m², more particularly between 13g/m² and 15 g/m². The thickness of the rolling paper may be between 5micrometers and 100 micrometers, in particular between 10 micrometersand 60 micrometers, more particularly between 20 micrometers and 50micrometers.

Within the meaning of the present invention, the term “web ofroll-your-own cigarette paper” is understood to mean roll-your-owncigarette paper as described above, the general shape of which, once theweb is unrolled, is a rectangle. Typically, the length of the rectangleis several tens of meters, indeed even several thousand meters, whileits width is greater than or equal to 0.6 m, in particular greater thanor equal to 1 m, more particularly greater than or equal to 1.2 m, moreparticularly still greater than or equal to 1.5 m.

Within the meaning of the present invention, the term “bobbin ofroll-your-own cigarette paper” is understood to mean roll-your-owncigarette paper as described above, the general shape of which, once thebobbin is unrolled, is a rectangle and which can comprise amoisture-activatable adhesive strip along one of the long edges of therectangle. The width of the rectangle is substantially equal to thewidth of the sheets of roll-your-own cigarette paper, i.e. between 30 mmand 75 mm, in particular approximately 36 mm, approximately 44 mm orapproximately 53 mm. Typically, the length of the rectangle is fromseveral hundred to several thousand meters, for example between 1000 mand 15 000 m, in particular between 3000 m and 10 000 m, veryparticularly between 5000 m and 8000 m. The length of the rectangle canalso be one or more tens of meters; in this case, the sheet is known asroll. The length of the rectangle can also be one or more meters; inthis case, the sheet is known as ream.

The moisture-activatable adhesive strip (also denoted adhesive strip)comprises a moisture-activatable adhesive.

Within the meaning of the present invention, the term“moisture-activatable adhesive” is understood to mean a compound whichexhibits an adhesive property on contact with water or with moisture,such as, for example, the saliva. The moisture-activatable adhesive(also denoted adhesive) may be any type of adhesive known to a personskilled in the art. For example, the adhesive can be chosen from sugarsolutions, modified or unmodified polysaccharides, gums and mixturesthereof, in particular gums.

Mention may be made, as modified or unmodified polysaccharides, ofstarch, alginates, dextrins, cyclodextrins or mixtures thereof.

The gums may be natural or artificial. Examples of natural gums areacacia gum, gum arabic, guar gum, karaya gum or pectins, in particulargum arabic.

The mass concentration of moisture-activatable adhesive in the adhesivestrip of the bobbin of roll-your-own cigarette paper, without takinginto account the roll-your-own cigarette paper, can, for example, be atleast 95%, in particular at least 97%, more particularly at least 99%,more particularly still 100%.

The adhesive strip can also comprise an additive for conferring aproperty other than the adhesiveness on the adhesive strip.

For example, the additive can be a plasticizer, an antifoaming agent, acolorant, an aromatic compound or mixtures thereof, in particular aplasticizer, an antifoaming agent or mixture thereof.

Sorbitol is an example of plasticizer which can be used in the contextof the present invention.

Mention may be made, as colorant, of natural or artificial foodcolorants, in particular natural food colorants. Caramels,chlorophyllin, the colorant resulting from paprika, the colorantresulting from beetroot, carotene, the colorant resulting from turmeric,cochineal, the colorant resulting from annatto seed, lutein, thecolorant resulting from sunflower, anthocyanins, the colorant resultingfrom malt, charcoal and thermoluminescent pigments are examples ofnatural food colorants.

The aromatic compound can be chosen from glycosylated modifiedflavorings, encapsulated flavorings (cyclodextrins, membranes ormatrices), natural flavorings and mixtures thereof. The aromaticcompound can in particular be chosen from EVG, emanates, synthetic ornatural cannabidiol (CBD), synthetic or natural tetrahydrocannabinol(THC), terpenes and mixtures thereof.

The grammage of the adhesive strip depends on the technology employed instep a). Typically, the grammage of the adhesive strip, excluding theroll-your-own cigarette paper, is less than 8 g/m², in particularbetween 5.5 g/m² and 7.5 g/m², more particularly between 5 g/m² and 6.5g/m².

The grammage of the adhesive strip is determined by weighing the weightof 1 m² of a zone of the bobbin of paper devoid of adhesive strip, byweighing the weight of 1 m² of a zone of the bobbin of paper comprisingadhesive strip and by subtracting the two weights.

Typically, the width of the adhesive strip is between 1 mm and 10 mm, inparticular between 4 mm and 8 mm, more particularly between 5 mm and 7mm.

The adhesive strip can have a continuous or non-continuous form.

Mention may be made, as form of continuous form, of a straight line, azigzag pattern, a crenellated pattern or a wave pattern.

Examples of non-continuous form are a non-continuous line of geometricshapes, of logos or mixtures thereof. The line can be straight orcurved.

Examples of geometric shape are a polygon, a circle, an ellipse, an ovalor mixtures thereof. The polygon can be a triangle, a quadrilateral,such as a square, a rectangle or a diamond, a pentagon, a hexagon or anoctagon.

The logo can be a logo of a manufacturer of roll-your-own cigarettepaper.

According to one embodiment, n is an integer of less than 100, inparticular of between 30 and 55.

Step a) can, for example, be carried out at a rate of forwardprogression of the paper of greater than or equal to 70 m/min, inparticular of greater than or equal to 100 m/min, more particularly ofgreater than or equal to 150 m/min, more particularly still of greaterthan or equal to 200 m/min.

Step a) can be carried out by any technique known to a person skilled inthe art. For example, step a) can be carried out with amoisture-activatable adhesive solution and by techniques such asetching, flexography, heliography, flexogravure, photogravure, spraying,wetting and immersion, in particular flexography, heliography,flexogravure and photogravure. Each of these techniques can be followedby drying.

According to a specific embodiment, step a) is carried out byflexography, followed, if need be, by drying.

Flexography is a relief printing process known to a person skilled inthe art in which a flexible relief plate, known as negative, isimpregnated with a printing solution, and the substrate and theimpregnated negative are brought into contact in order for the printingsolution to be applied to the substrate.

In the context of the present invention, flexography advantageouslymakes it possible to bring n negatives impregnated with the solution ofmoisture-activatable adhesive into contact with the web of roll-your-owncigarette paper in order to make possible the application of the nstrips of adhesives to the web of roll-your-own cigarette paper.

Flexography also makes it possible to have a rate of forward progressionof the paper which can be four times greater than the rate ofconventional processes. Thus, the productivity of the process for themanufacture of a bobbin of roll-your-own cigarette paper of theinvention is thus greater than conventional processes.

In addition to the speed and to the use of the n negatives, flexographyis a gentle application method which makes it possible to greatly reducethe risk of tearing of the web of roll-your-own cigarette paper whenstep a) is carried out.

Mention may be made, among the other advantages offered by flexography,of the accuracy, the simplicity and the low cost price of the negatives.

In addition, flexography is a flexible method which makes it possible toobtain an adhesive strip, the shape of which depends on the shape of thenegative.

Furthermore, the tensile strength in the machine direction and in thetransverse direction of the bobbins manufactured after step a) carriedout by flexography is greater than that of the bobbins manufactured by aconventional process The bobbins manufactured after step a) carried outby flexography can thus more easily be employed in steps subsequent tothe process for the manufacture of the bobbins of the invention, suchas, for example, a step of cutting the bobbin into sheets or a step offormation of a stack of bobbins followed by a step of cutting the stackinto a stack of sheets.

The moisture-activatable adhesive solution (also denoted adhesivesolution) comprises a moisture-activatable adhesive. The massconcentration of moisture-activatable adhesive in the adhesive solutioncan be between 30% and 60%, in particular between 32% and 45%, moreparticularly between 35% and 40%.

The adhesive solution is typically an aqueous solution. Themoisture-activatable adhesive solution can also comprise an additive asdescribed above.

According to a specific embodiment, the adhesive solution can comprise amoisture-activatable adhesive, a plasticizer and an antifoaming agent,and the mass concentration of moisture-activatable adhesive is from 30%to 50%, the mass concentration of plasticizer is from 0.1% to 0.5% andthe mass concentration of antifoaming agent is from 0.5% to 1%.

FIG. 1 illustrates an adhesive web of paper 1 at the end of step a) ofthe process of the invention comprising four adhesive strips 2 appliedthereon.

Step b) of cutting the adhesive web of paper is a conventional cuttingstep known to a person skilled in the art. The latter will thus know howto adapt the process for the manufacture of a bobbin of roll-your-owncigarette paper of the invention.

The step b) of cutting can, for example, be carried out at a rate offorward progression of the paper of greater than or equal to 100 m/min,in particular of greater than or equal to 500 m/min, more particularlyof greater than or equal to 750 m/min, more particularly still ofgreater than or equal to 1000 m/min.

FIG. 2 illustrates four bobbins of roll-your-own cigarette paper 11,each bobbin 11 comprising an adhesive strip 2 along one of these twolong edges.

A bobbin manufactured by the process of the invention can be cut into asheet of roll-your-own cigarette paper which will subsequently be usedto form a roll-your-own cigarette.

Another aspect of the invention is thus a process for the manufacture ofa sheet of roll-your-own cigarette paper comprising a step c) of cuttingat least one bobbin of roll-your-own cigarette paper manufactured by theprocess for the manufacture of a bobbin of roll-your-own cigarette paperdescribed above in order to manufacture a sheet of roll-your-owncigarette paper.

Within the meaning of the invention, the term “sheet of roll-your-owncigarette paper” is understood to mean roll-your-own cigarette paper asdescribed above, the general shape of which is a rectangle and whichcomprises an adhesive strip as described above along one of the longedges of the rectangle. Typically, the length of the rectangle isbetween 50 mm and 110 mm, while its width can vary from 30 mm to 75 mm.

Step c) of cutting the bobbin of roll-your-own cigarette paper is aconventional cutting step known to a person skilled in the art. Thelatter will thus know how to adapt the process for the manufacture of asheet of roll-your-own cigarette paper of the invention.

The sheet of roll-your-own cigarette paper manufactured by the processof the invention is conventionally sold in the form of a booklet.

The invention thus also relates to a process for the manufacture of abooklet of sheets of roll-your-own cigarette paper comprising a step d1)of formation of a stack of sheets of roll-your-own cigarette paper whichare manufactured by the process for the manufacture of a sheet ofroll-your-own cigarette paper of the invention.

The formation step d1) can, for example, be carried out by stacking thesheets of roll-your-own cigarette paper on one another or by inserting asheet of roll-your-own cigarette paper between two sheets ofroll-your-own cigarette paper.

For example, the formation step d1) can be carried out by inserting thesheets using the item of equipment sold by IMAtec in Luxembourg.

According to one embodiment, the stack of sheets which is formed afterstep d1) can undergo an interlocking step in order to form a stack ofinterlocked sheets.

The stack of sheets, which are or are not interlocked, can subsequentlybe introduced into a carrying case.

The invention thus also relates to a process for the manufacture of abooklet of sheets of roll-your-own cigarette paper comprising a step d2)of formation of a stack of bobbins of roll-your-own cigarette paperwhich are manufactured by the process for the manufacture of a bobbin ofroll-your-own cigarette paper of the invention, followed by a step e) ofcutting the stack of bobbins.

The stack of bobbins can be formed during step d2) by unrolling thebobbins of roll-your-own cigarette paper and stacking the unrolledbobbins of roll-your-own cigarette paper on one another or by insertingone unrolled bobbin of roll-your-own cigarette paper between twounrolled bobbins of roll-your-own cigarette paper.

According to one embodiment, the stack of sheets which is formed in stepe) of cutting the stack of bobbins can undergo an interlocking step inorder to form a stack of interlocked sheets.

According to one embodiment, the stack of bobbins which is formed instep d2) can undergo an interlocking step before the step of cutting inorder to form a stack of interlocked sheets.

The stack of sheets, which are or are not interlocked, can subsequentlybe introduced into a carrying case.

EXAMPLE Example 1 According to the Invention

An aqueous solution of gum arabic is applied by flexography to a web ofroll-your-own cigarette paper so that four adhesive strips extend in themachine direction. The web is subsequently dried and then cut in orderto obtain four bobbins, each bobbin comprising an adhesive stripcomprising gum arabic.

The bobbin is subsequently cut into sheets.

Each sheet exhibits a rectangular shape with a length of 110 mm, a widthof 44 mm and a continuous adhesive strip along one of the two long edgesof the sheet.

By virtue of this process, the sheets are produced at a rate of 200m/min.

Comparative Example 2

A web of paper is cut into four bobbins.

An aqueous solution of gum arabic is applied by a nozzle to each bobbinof roll-your-own cigarette paper. Each bobbin is subsequently dried andthen cut into sheets.

Each sheet exhibits a rectangular shape with a length of 110 mm, a widthof 44 mm and a continuous adhesive strip along one of the two long edgesof the sheet.

The sheets are produced at a rate of 55 m/min with the process accordingto comparative example 2.

The process for the manufacture of the sheet of example 1 (according tothe invention) is thus four times faster than the process for themanufacture of the sheet of example 2 (comparative).

The productivity of the process of example 1 is thus greater than theproductivity of the process of example 2.

1. Process for the manufacture of bobbins of roll-your-own cigarettepaper comprising the following steps: a) applying n moisture-activatableadhesive strips to a web of roll-your-own cigarette paper in order toobtain an adhesive web of paper, each of the n moisture-activatableadhesive strips extending in the machine direction, and b) cutting theadhesive web of paper in the machine direction along the n-1moisture-activatable adhesive strips in order to obtain n bobbins ofroll-your-own cigarette paper, each bobbin of roll-your-own cigarettepaper comprising a moisture-activatable adhesive strip along one ofthese long edges, n being an integer greater than or equal to
 2. 2.Process according to claim 1, in which the moisture-activatable adhesiveis chosen from sugar solutions, polysaccharides, starch and gums andtheir mixtures.
 3. Process according to claim 1 or claim 2, in whichstep a) is carried out with a moisture-activatable adhesive solution andby techniques such as etching, flexography, heliography, flexogravure,photogravure, spraying, wetting and immersion, in particularflexography, heliography, flexogravure and photogravure.
 4. Processaccording to any one of claims 1 to 3, in which step a) is carried outby flexography.
 5. Process according to any one of claims 1 to 4, inwhich the moisture-activatable adhesive strip exhibits a grammage ofless than 8 g/m².
 6. Process according to any one of claims 1 to 5, inwhich the moisture-activatable adhesive strip exhibits a continuous formor a non-continuous form.
 7. Process according to claim 6, in which thecontinuous form is chosen from a straight line, a zigzag pattern, acrenellated pattern or a wave pattern.
 8. Process according to claim 6,in which the non-continuous form is chosen from a non-continuous line ofpolygons, a non-continuous line of geometric shapes, of logos andmixtures thereof.
 9. Process for the manufacture of a sheet ofroll-your-own cigarette paper comprising a step c) of cutting a bobbinof roll-your-own cigarette paper manufactured by the process as definedin any one of claims 1 to 8 in order to manufacture a sheet ofroll-your-own cigarette paper.
 10. Process for the manufacture of abooklet of sheets of roll-your-own cigarette paper comprising a step d1)of formation of a stack of sheets of roll-your-own cigarette paper whichare manufactured by the process as defined in claim
 9. 11. Process forthe manufacture of a booklet of sheets of roll-your-own cigarette papercomprising a step d2) of formation of a stack of bobbins ofroll-your-own cigarette paper which are manufactured by the process asdefined in any one of claims 1 to 8, followed by a step e) of cuttingthe stack of bobbins in order to form a stack of sheets.
 12. Processaccording to claim 10 or claim 11, in which the stack of sheets formedin step d1) or in step e) of cutting the stack of bobbins undergoes aninterlocking step in order to form a stack of interlocked sheets. 13.Process according to claim 11, in which the stack of bobbins which isformed in step d2) undergoes an interlocking step before the step ofcutting the stack of bobbins in order to form a stack of interlockedsheets.